An antenna device is incorporated into an electronic apparatus and is able to communicate by receiving a magnetic field transmitted from a reader/writer (120). The antenna device includes an antenna substrate (11), an antenna coil (11a) formed so as to loop around on one surface of the antenna substrate (11), a magnetic sheet (13) inserted into a central section of the antenna coil (11a) to pull in the magnetic field transmitted from the reader/writer (120), and a circuit section that is mounted in a shared circuit mounting region (20) provided on the other surface of the antenna substrate (11) at a position that avoids a position at which the magnetic sheet (13) is inserted and that is connected to an external circuit. At least part of a winding wire of the antenna coil (11a) surrounds at least a portion of circuit components forming the circuit section.